Antiseptic toothbrushes



United States Patent ANTISEPTIC TOOTHBRUSHES Murray W. Rosenthal,Nutley, NJ., assignor to Pycop, Inc., Jersey City, NJ., a corporation ofMissouri No Drawing. Filed July 6, 1956, Ser. No. 596,140

6 Claims. 01. -159 This application relates to the production oftoothbrushes with germicidal properties, and its aim is to producetoothbrushes which are treated so as to have active bacteria inhibitingproperties, and which retain these properties during the normal life ofthe brushes, without injury to the appearance of the toothbrushes.According to my invention, I treat toothbrushes, or components thereofbefore assembly, with an essentially aqueous and colloidal dispersion ofan aromatic mercury compound which is normally insoluble or veryslightly soluble in cold water, the dispersion containing a minorquantity of a bactericidal quaternary ammonium compound, and a non-ionicwetting agent to disperse the product evenly and to enhance thepenetration of the germicidal ingredients to the toothbrush components.

It has been proposed to treat various materials including toothbrusheswith aromatic mercury compounds and also to treat them with bactericidalquaternary ammonium compounds, to give them bacteria inhibitingproperties. The principal difiiculty with the treatments, especially ontoothbrushes, has been that the bacteria inhibiting properties disappearsoon after the toothbrushes are put in use. The apparent reason is thatthe dentifrices used when admixed with water or saliva have fairlystrong detergent action, and remove the active materials too rapidly bya combination of solution and emulsification with subsequent leaching.

I have discovered that toothbrushes can be treated so as to give thembacteria inhibitive properties which they retain for up to a six monthperiod of active use (the normal life of a toothbrush in active use.According to my invention, I treat the toothbrushes, or their componentsbefore assembly, with an essentially aqueous dispersion of an aromaticmercury compound which is either insoluble or only slightly soluble incold water, together with a minor amount of a bactericidal quaternaryammonium compound, using a nonionic dispersant to disperse the aromaticmercury compound. The toothbrushes are immersed in the solution for arelatively short time (30 seconds to 30 minutes) and are then Withdrawnand dried, either with or without a water rinse before drymg.

The treatment is applicable to natural hog and other animal bristlebrushes and to brushes with nylon bristles, and to handles of thevarious plastics used in the toothbrush industry including celluloseacetate, cellulose acetate butyrate and other conventionally used moldedplastics.

Tests made on toothbrushes in daily use over a six month period indicatethat the brushes retain their bacteria inhibitive properties over thisperiod of normal useful life.

The nonionic dispersing agent has a two-fold function in thecomposition. It makes possible the use of considerably higherconcentrations of aromatic mercury compounds than are soluble in thewater alone. Sec- 2,939,164 Patented June 7, 1960 ondly, it acts as apenetrating agent, depositing the mar-'- I can use any;of the aromaticmercury compounds which are insoluble or only slightly soluble in coldwater. I have used phenyl mercuric chloride, nitrate and propionate,p-tolyl mercuric salts, p-hydroxy phenyl mercuric derivatives, pyridylmercuric compounds, etc.

I may use any quaternary ammonium compound which is germicidal innature. (See .Lawrence-Surface-Active Quaternary Ammonium Germicides-NewYork, 1950.) These quaternary ammonium compounds are generally excellentWetting agents. Typical of the products which may be used are the cetyland other long chain alkyl trimethyl ammonium halides, the pyridiniumand related heterocyclic alkyl halides, the aryl alkyl and thesubstituted 'aryl alkyl quaternary ammonium halides, and the like.

I use a small amount of quaternary ammonium compound relative to thearomatic mercury compound. In general, I use from about 2 to 20% of thequaternary based on the mercury compound.

The nonionic dispersants I have used include the polyoxyethylenesorbitan long chain fatty acid derivatives, the polyoxyethylene andpolyoxypropylene alkyl phenols, the polyoxyethylene and polyoxypropylenefatty acid ethers, and polyoxyethylene-polyoxypropylene condensates.

Necessary treatment time may vary from 30 seconds up, depending onconditions. I prefer to operatae at slightly elevated temperatures (50C. up to the boiling point) to speed penetration. I find that 30 minutesimmersion time is adequate under the mildest conditions; 5 minutes isgenerally adequate.

Typical examples of treating solutions are the Hexadecyldimethyl benzylammonium chloride 0.06 Water to Example 4 Percent Phenyl mercuricpropionate 0.90 Igepal C0430 (polyoxyethylene alkyl phenol) 2.0Hexadecyl pyridinium bromide 0.05 Ethyl alcohol 16 Water to 100%.

ing an extended usage period, which comprises immersing,

the components of a toothbrush for between 3Qi secondsv and 30 minutes,at atemperature between150 C. and the boiling point, in an aqueousdispersion containing a nonionic dispersant, more aromatic mercurycompound than is. soluble in the water alone,, and a minor proportion byweight, as compared with, the aromatic'mercury com-t pound, 'of' agermicidal quaternary ammonium compound, removing thev components of-thetoothbrush from.

the dispersion, anddrying.

2. The method of claim 1, in which; the weight of quaternary ammoniumcompound is between-.2; and 20% of the weight ofaromaticmercurycompound; r

3. An aqueous dispersion for treating pIastic-handl'ed' toothbrushes torender them bacteria-inhibitive, comprising water containing a non-ionicdispersant, more; aromatic mercury compound than is soluble in the wateralone, and a minor proportion by weight; as comparedwith the mercurycompound, of a germicidal quaternary.

ammonium compound.

4. The dispersion of claim 3, in which the weight of quaternary ammoniumcompound'j is between 2 and' 20% of the weight of the aromatic mercurycompound.

5. A toothbrush having a plastic handle and bristles of the classconsisting of animal bristles and plastic bristles, said toothbrushcarrying a bacteria inhibitive impregnant comprising an aromatic mercurycompound of very low water solubility, a-non-ionic dispersant and aminor proportiomby weight, basedon, t hearomatic mercury compound, of agermicidal quaternary ammonium compound, the brush beingcharacterized byits retention of bacteria inhibitive properties over long periods ofuse.

6. The toothbrush 0t claim in. which, the weight of quaternary ammoniumcompound is between 2 and 20% of the weight of aromatic, mercury:compound.

References Cited in the file of this patent UNITED STATES PATENTS Hill.et al- ,s Nov. 23,1937 2,264,150 Hueter et a1, Nov. '25,; 1941 2,411,815Sowa Nov; 26,1946 2,423,262 Sowa .V V July 1 1,947 2,505,681, Margot..-e -r r .t. r Apr. 25, 1950 2,507,299. Addison May.9, 1-950 FOREIGNPATENTS The Bulletin American Society of Hospital

1. THE METHOD OF MAKING A PLASTIC-HANDLED TOOTHBRUSH HAVING BACTERIAINHIBITIVE PROPERTIES WHICH IT RETAINS DURING AN EXTENDED USAGE PERIOD,WHICH COMPRISES IMMERSING THE COMPONENTS OF A TOOTHBRUSH FOR BETWEEN 30SECONDS AND 30 MINUTES, AT A TEMPERATURE BETWEEN 50*C. AND THE BOILINGPOINT, IN AN AQUEOUS DISPERSION CONTAINING A NONIONIC DISPERSANT, MOREAROMATIC MERCURY COMPOUND THAN IS SOLUBLE IN THE WATER ALONE, AND AMINOR PROPORTION BY WEIGHT, AS COMPARED WITH THE AROMATIC MERCURYCOMPOUND, OF A GERMICIDAL QUATERNARY AMMONIUM COMPOUND, REMOVING THECOMPONENTS OF THE TOOTHBRUSH FROM THE DISPERSION, AND DRYING.